/*
 * Copyright (c) 2001, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package com.sun.imageio.plugins.jpeg;

//import javax.imageio.IIOException;

import javax.imageio.metadata.IIOInvalidTreeException;
import javax.imageio.metadata.IIOMetadataNode;
import javax.imageio.stream.ImageOutputStream;

import java.io.IOException;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.NamedNodeMap;

/**
 * An SOS (Start Of Scan) marker segment.
 */
class SOSMarkerSegment extends MarkerSegment {

  int startSpectralSelection;
  int endSpectralSelection;
  int approxHigh;
  int approxLow;
  ScanComponentSpec[] componentSpecs; // Array size is numScanComponents

  SOSMarkerSegment(boolean willSubsample,
      byte[] componentIDs,
      int numComponents) {
    super(JPEG.SOS);
    startSpectralSelection = 0;
    endSpectralSelection = 63;
    approxHigh = 0;
    approxLow = 0;
    componentSpecs = new ScanComponentSpec[numComponents];
    for (int i = 0; i < numComponents; i++) {
      int tableSel = 0;
      if (willSubsample) {
        if ((i == 1) || (i == 2)) {
          tableSel = 1;
        }
      }
      componentSpecs[i] = new ScanComponentSpec(componentIDs[i],
          tableSel);
    }
  }

  SOSMarkerSegment(JPEGBuffer buffer) throws IOException {
    super(buffer);
    int numComponents = buffer.buf[buffer.bufPtr++];
    componentSpecs = new ScanComponentSpec[numComponents];
    for (int i = 0; i < numComponents; i++) {
      componentSpecs[i] = new ScanComponentSpec(buffer);
    }
    startSpectralSelection = buffer.buf[buffer.bufPtr++];
    endSpectralSelection = buffer.buf[buffer.bufPtr++];
    approxHigh = buffer.buf[buffer.bufPtr] >> 4;
    approxLow = buffer.buf[buffer.bufPtr++] & 0xf;
    buffer.bufAvail -= length;
  }

  SOSMarkerSegment(Node node) throws IIOInvalidTreeException {
    super(JPEG.SOS);
    startSpectralSelection = 0;
    endSpectralSelection = 63;
    approxHigh = 0;
    approxLow = 0;
    updateFromNativeNode(node, true);
  }

  protected Object clone() {
    SOSMarkerSegment newGuy = (SOSMarkerSegment) super.clone();
    if (componentSpecs != null) {
      newGuy.componentSpecs =
          (ScanComponentSpec[]) componentSpecs.clone();
      for (int i = 0; i < componentSpecs.length; i++) {
        newGuy.componentSpecs[i] =
            (ScanComponentSpec) componentSpecs[i].clone();
      }
    }
    return newGuy;
  }

  IIOMetadataNode getNativeNode() {
    IIOMetadataNode node = new IIOMetadataNode("sos");
    node.setAttribute("numScanComponents",
        Integer.toString(componentSpecs.length));
    node.setAttribute("startSpectralSelection",
        Integer.toString(startSpectralSelection));
    node.setAttribute("endSpectralSelection",
        Integer.toString(endSpectralSelection));
    node.setAttribute("approxHigh",
        Integer.toString(approxHigh));
    node.setAttribute("approxLow",
        Integer.toString(approxLow));
    for (int i = 0; i < componentSpecs.length; i++) {
      node.appendChild(componentSpecs[i].getNativeNode());
    }

    return node;
  }

  void updateFromNativeNode(Node node, boolean fromScratch)
      throws IIOInvalidTreeException {
    NamedNodeMap attrs = node.getAttributes();
    int numComponents = getAttributeValue(node, attrs, "numScanComponents",
        1, 4, true);
    int value = getAttributeValue(node, attrs, "startSpectralSelection",
        0, 63, false);
    startSpectralSelection = (value != -1) ? value : startSpectralSelection;
    value = getAttributeValue(node, attrs, "endSpectralSelection",
        0, 63, false);
    endSpectralSelection = (value != -1) ? value : endSpectralSelection;
    value = getAttributeValue(node, attrs, "approxHigh", 0, 15, false);
    approxHigh = (value != -1) ? value : approxHigh;
    value = getAttributeValue(node, attrs, "approxLow", 0, 15, false);
    approxLow = (value != -1) ? value : approxLow;

    // Now the children
    NodeList children = node.getChildNodes();
    if (children.getLength() != numComponents) {
      throw new IIOInvalidTreeException
          ("numScanComponents must match the number of children", node);
    }
    componentSpecs = new ScanComponentSpec[numComponents];
    for (int i = 0; i < numComponents; i++) {
      componentSpecs[i] = new ScanComponentSpec(children.item(i));
    }
  }

  /**
   * Writes the data for this segment to the stream in
   * valid JPEG format.
   */
  void write(ImageOutputStream ios) throws IOException {
    // We don't write SOS segments; the IJG library does.
  }

  void print() {
    printTag("SOS");
    System.out.print("Start spectral selection: ");
    System.out.println(startSpectralSelection);
    System.out.print("End spectral selection: ");
    System.out.println(endSpectralSelection);
    System.out.print("Approx high: ");
    System.out.println(approxHigh);
    System.out.print("Approx low: ");
    System.out.println(approxLow);
    System.out.print("Num scan components: ");
    System.out.println(componentSpecs.length);
    for (int i = 0; i < componentSpecs.length; i++) {
      componentSpecs[i].print();
    }
  }

  ScanComponentSpec getScanComponentSpec(byte componentSel, int tableSel) {
    return new ScanComponentSpec(componentSel, tableSel);
  }

  /**
   * A scan component spec within an SOS marker segment.
   */
  class ScanComponentSpec implements Cloneable {

    int componentSelector;
    int dcHuffTable;
    int acHuffTable;

    ScanComponentSpec(byte componentSel, int tableSel) {
      componentSelector = componentSel;
      dcHuffTable = tableSel;
      acHuffTable = tableSel;
    }

    ScanComponentSpec(JPEGBuffer buffer) {
      // Parent already loaded the buffer
      componentSelector = buffer.buf[buffer.bufPtr++];
      dcHuffTable = buffer.buf[buffer.bufPtr] >> 4;
      acHuffTable = buffer.buf[buffer.bufPtr++] & 0xf;
    }

    ScanComponentSpec(Node node) throws IIOInvalidTreeException {
      NamedNodeMap attrs = node.getAttributes();
      componentSelector = getAttributeValue(node, attrs, "componentSelector",
          0, 255, true);
      dcHuffTable = getAttributeValue(node, attrs, "dcHuffTable",
          0, 3, true);
      acHuffTable = getAttributeValue(node, attrs, "acHuffTable",
          0, 3, true);
    }

    protected Object clone() {
      try {
        return super.clone();
      } catch (CloneNotSupportedException e) {
      } // won't happen
      return null;
    }

    IIOMetadataNode getNativeNode() {
      IIOMetadataNode node = new IIOMetadataNode("scanComponentSpec");
      node.setAttribute("componentSelector",
          Integer.toString(componentSelector));
      node.setAttribute("dcHuffTable",
          Integer.toString(dcHuffTable));
      node.setAttribute("acHuffTable",
          Integer.toString(acHuffTable));
      return node;
    }

    void print() {
      System.out.print("Component Selector: ");
      System.out.println(componentSelector);
      System.out.print("DC huffman table: ");
      System.out.println(dcHuffTable);
      System.out.print("AC huffman table: ");
      System.out.println(acHuffTable);
    }
  }

}
